C2-ung or CM2-an
standby for nwa 7821 photo
Purchased 2012

Eight fragments of a single meteorite having a combined weight of 38 g were found in the desert region of Northwest Africa. The pieces were sold at the 2013 Tucson Gem and Mineral Show to G. Hupé. A type sample was submitted for analyses and classification to the University of Washington at Seattle (A. Irving and S. Kuehner), and NWA 7821 was determined to be a new ungrouped C2 chondrite, or alternatively, an anomalous member of the CM chondrite group.

Northwest Africa 7821 is a low-density carbonaceous chondrite containing scattered granular chondrules ranging in size from 0.1 to 0.4 mm. CAIs are present in a fine-grained matrix having a composition similar to that of CM chondrites. The meteorite has been shocked to S2 and terrestrially weathered to a grade of W2. On an oxygen three-isotope diagram, NWA 7821 plots along the CM trend line for CM chondrites but with a higher than normal 16O content (Carnegie Institution, Washington D.C. (D. Rumble; see O-isotopic diagram). The specimen of NWA 7821 shown above is a 0.056 g partial slice. The photo shown below is one of the larger slices photographed by G. Hupé.

standby for nwa 7821 photo
Photo courtesy of Greg Hupé—Nature's Vault